LOS ANGELES (AP) -- A TV reporter who lapsed into gibberish during a live shot outside the Grammys said she was terrified when it happened and knew something was wrong as soon as she opened her mouth.

KCBS-TV reporter Serene Branson's incoherence Sunday fueled Internet speculation that she suffered an on-air stroke. But doctors at the University of California, Los Angeles, where she went to get a brain scan and blood work done, ruled it out. Doctors said she suffered a type of migraine that can mimic symptoms of a stroke.

Branson told CBS' "The Early Show" in an interview Friday that she was terrified, scared and confused, and didn't know what was going on.

"I knew something wasn't right as soon as I opened my mouth," she said. "I hadn't been feeling well a little bit before the live shot. I had a headache, my vision was very blurry. I knew something wasn't right, but I just thought I was tired. So when I opened my mouth, I thought, 'This is more than just being tired. Something is terribly wrong.' I wanted to say, 'Lady Antebellum swept the Grammys.' And I could think of the words, but I could not get them coming out properly."

Branson, who was diagnosed with migraine aura, said watching herself in the clip is "troubling."

Kerry Maller, a KCBS producer, told "The Early Show," "You could see in the tape she's trying to talk."

Maller, who was on-location with the veteran reporter, said, "After the live shot, she dropped the microphone and got very wobbly."

The station quickly cut away and Branson was swarmed by photographers and her field producer. She was examined by paramedics and recovered at home.

Branson recalled, "They sat me down immediately. I dropped the microphone. Right after that, my cheek went numb, my hand went numb, my right hand went numb and I started to cry. I was scared. I didn't know what had gone on and I was embarrassed and fearful.

"I was scared, nervous, confused, exhausted, and in an evening dress in the back of an ambulance."

She returned to the KCBS-TV newsroom on Thursday.

Most people with migraines don't have any warning. But about 20 to 30 percent experience sensations before or during a migraine attack.

"A migraine is not just a headache. It's a complicated brain event," said UCLA neurologist Dr. Andrew Charles, who examined Branson.

The most common sensations include seeing flashes of light or zigzag patterns. In Branson's case, she felt numbness on the right side of her face that affected her speech, Charles said.

"She was actually having the headache while she was having these other symptoms," he said.

Branson told doctors she has had migraines since a child but never suffered an episode like this before, Charles said.

Branson, a Los Angeles native and two-time Emmy nominee, worked at the CBS affiliate in Sacramento before joining KCBS. Prior to that, she was a reporter and anchor at TV stations in Palm Springs and Santa Barbara.

A telephone message left with KCBS was not immediately returned Thursday.